[Technical Field]
The present invention relates to a technology for selecting a vehicle (preceding vehicle) that is traveling ahead of an own vehicle.
[Related Art]
As a technology for reducing operating load placed on a driver who is driving a vehicle, an inter-vehicle control apparatus is known. The inter-vehicle control apparatus detects a vehicle (preceding vehicle) that is traveling ahead of the own vehicle. The inter-vehicle control apparatus controls the vehicle speed and the like to maintain a certain distance between the own vehicle and the preceding vehicle, enabling the own vehicle to automatically track the preceding vehicle.
In this type of apparatus, an estimated curve radius of the road on which the own vehicle is traveling is determined based on the yaw rate and vehicle speed of the own vehicle. In addition, a radar apparatus or the like is used to detect the position of the vehicle that is present ahead of the own vehicle. Based on the estimated curve radius and the position of the preceding vehicle, an own vehicle lane probability is determined for each detected preceding vehicle. The own vehicle lane probability indicates the probability of the vehicle being present on the estimated traveling lane of the own vehicle. Selection of a preceding vehicle and cancellation of the selection are performed based on the own vehicle lane probability.
Furthermore, because the detection values of the yaw rate vary, the calculation results for the estimated curve radius also vary. Therefore, to suppress the effects caused by the variation, a filter calculation is performed on the own vehicle lane probability (for example, refer to JP-B-3427815).
Regarding a vehicle that is temporarily selected as a preceding vehicle, highly stable selection is required so that the selection is not erroneously canceled by noise or the like. On the other hand, regarding a non-preceding vehicle that is a vehicle other than the preceding vehicle, responsive selection is required so that, when a non-preceding vehicle cuts in ahead of the own vehicle, this situation is promptly detected.
Such stability and responsiveness can be actualized by the characteristics of the filter calculation. However, stability and responsiveness are contradictory requests. Therefore, a problem occurs in that it is difficult to perform a filter calculation that is suitable for both a preceding vehicle and a non-preceding vehicle.